1. Field of the Invention
This invention relates to a chainsaw attachment which facilitates the measuring and cutting of a log into uniform lengths of firewood. More particularly, it relates to a chain saw attachment that substantially improves the accuracy and composure of measuring and cutting of uniform lengths of firewood in rapid succession without continual re-adjustment and does so with a safe, effortless, non-intrusive and versatile means of attachment to any chain saw bar.
There is a need for uniform cut firewood to conform to the size of a particular stove, big enough to fill the firebox acquiring maximum BTU output, yet small enough to fit through the opening. Uniform firewood is also easier to handle and transport than oddly cut pieces. A tight stack of uniform firewood not only is pleasing to the eye and space saving, it assures the customer of sufficient volume acquired.
2. Prior Art Statement
In the past the entire log was measured and hand marked before cutting. Items used for measuring include a tape measure, a yard stick, a piece of pre-cut wood, etc. Items used for marking include an axe, a hand saw, a pencil, spray paint, etc. This method is extremely time consuming and hazardous. It also requires hauling of these cumbersome items. U.S. Pat. No. 7,051,444, Benny A. Hofer, May 30, 2006 demonstrates a modern version of this method.
A more efficient method would be the use of a chainsaw attachment, incorporating the marking and cutting in one operation. It is generally known that this attachment would encompass a linear device of measured length extending perpendicular to the cutting plane of the chainsaw. When the opposing end of the linear device is aligned with the log end, the measured length of the cut becomes evident.
Most previously proposed attachments are mounted to the motor housing or handle of the chainsaw. U.S. Pat. No. 4,185,382, John P. Rawlinson, Jr., Jan. 29, 1980, No. 4,388,762 DeBell, et al., Jun. 21, 1983 and No. 4,545,122, David L. Durfee, Jr., Oct. 8, 1985 all attach to the chain cover bolts. On some new chainsaws these bolts have been eliminated making these attachments inoperable. Others have different thread or bolt sizes therefore requiring alterations to fit different chainsaws. U.S. Pat. No. 4,299,034, Joseph G. DeBetta, Nov. 10, 1981, No. 4,319,404, Helmut E. Brock, Mar. 16, 1982, No. 4,341,018, Nelson, et al., Jul. 27, 1982 and No. 4,625,407 F. Patrick Wallis, Dec. 2, 1986, all of which clamp to the chainsaw handle. These clamps are obstructive and hazardous. The chainsaw handle was fashioned to allow the placement of the operator's grip at various places along this handle to accommodate for the different cuts being made. For instance, when felling a tree the saw would be rotated in a horizontal position thus changing the operators grip from the top of the handle to the side.
Other previously proposed attachments are mounted to the chainsaw bar. U.S. Pat. No. 4,377,910, Ernest J. Landry, Mar. 29, 1983 employs a clamping device. Should this clamp be vibrated loose or slip into the operating chain the results could inflict severe injury. U.S. Pat. No. 4,561,186 Arthur N. Keefe, Dec. 31, 1985 depends on two small magnets and two pegs. Although the pegs do prevent slippage it would be difficult drilling the two accompanying holes exactly the right distance apart. The small magnets would have insufficient holding power in the rough environment of wood cutting. There is no backup preventing this device from falling or being knocked off, thus creating a potential hazard. The lineal measuring device, a tape measure, would be too fragile for this environment and would require frequent replacement.
It is further known a chainsaw measuring attachment to rely on line of sight to achieve the measured length of the cut. For instance, see the aforementioned U.S. Pat. No. 4,319,404 to Brock and U.S. Pat. No. 4,984,371, Robert N. Fredrickson, Jan. 15, 1991. This method is inaccurate. It relies on position and angle of the saw in relation to the operator and the log. A lot of time and effort is spent to acquire the right position. U.S. Pat. No. 6,295,738, Joel V. Risch, Oct. 2, 2001 employs a light, also depending on position and angle of the saw.
It is necessary to have the ability to measure from either end of the log otherwise the operator would need to climb over the log to facilitate measurement from the other end. This could put the operator in a hazardous position, for instance the downhill side of the log. This is a deficiency of most prior art.
The chainsaw attachment must have a failsafe connection to the saw, preventing an impact with the moving chain. On the other hand it must have the ability to be attached and completely removed, fast and easy, without the use of tools. This necessity becomes evident in the falling of a tree, the removal of small branches, the transportation and storage of the saw, etc. This is also a deficiency of most, if not all, prior art.
Another necessary attribute of the chainsaw attachment would be the ability to easily lock the opposing end of the lineal device to the end of the log, expediting fast and accurate measurement. Some prior art examples are completely deficient in this aspect, forcing the operator to estimate the alignment of the lineal device and the end of the log. Other prior art examples incorporate only a small hooking device, for instance a tape measure end, at the opposing end of the lineal device. The vibration of a running chainsaw makes the locking of these small appendages over the end of the log a difficult operation frequently requiring several attempts.
Although most homeowners would have the need of only one size gauge, the entrepreneur has the need of an adjustable gauge. This adjustment must be securely locked into position preventing the time consuming task of continued re-adjustment. U.S. Pat. No. 4,233,739, Leslie W. Henrichs, Nov. 18, 1980 and previously mentioned DeBell, et al., and Keefe rely on frictionally held devices for this adjustment, for instance, a tape measure lock or a telescoping tube. A frictionally held device would prove to be insufficient in this rough terrain. Only the slightest bump will knock these devices out of adjustment. Yet other prior art examples rely on screws, set screws, or nuts. The vibration of the chainsaw alone can work these adjustments loose presenting a potentially hazardous condition and at the least causing continual re-adjustment.